Pin guide for printing head

ABSTRACT

The selectively reciprocable pins of a mosaic printing device are guided in a series of holes defined by corundum bearing plates. The holes are precisely oriented relative to the printing head by cementing the plates in a polygonal recess in a support, the sides of the recess precisely locating the plates relative to the support. The support in turn is fixed in the printing head with a plurality of flat surfaces on the support in contact with a plurality of flat surfaces on the printing head, thereby precisely to orient the support and hence the holes relative to the printing head.

United States Patent Juvet Dec. 23, 1975 PIN GUIDE FOR PRINTING IIEAD 3.8201143 6/1974 Priebs et a1. 197/1 R 75 l tzCld-M'hl t, l 1 men or 51 5 5 e Juve Les Brenets Primary Examiner-Edgar S. Burr Assistant Examiner-R. T. Rader [73] Assigneez Se|lz S.A., Les Brenets, Switzerland Attorney, Agent, or Firm-Young & Thompson [22] Filed: July 5, 1974 [21] A l N '486199 [57] ABSTRACT pp The selectively reciprocable pins of a mosaic printing device are guided in a series of holes defined by C0- [30] Foreign Application Priority Data rundum bearing plates. The holes are precisely ori- July 6, 1973 Switzerland 9863/73 emed relative to the Priming head y cementing the plates in a polygonal recess in a support, the sides of 52 us. (:1. 197/1 R; 308/15 the recess precisely locating the Plates relative to the 151 Im. c1. 841.] 3/04 pp The pp in turn is fixed in the Printing 581 Field of Search 197/1 R; 308/15, 26 head with a plurality of flat surfaces on the pp in contact with a plurality of flat surfaces on the printing 1 [56] References Cit d head, thereby precisely to orient the support and 1 hence the holes relative to the printing head.

3,802,543 4/1974 Howard 197/1 R 1 Claim, 6 Drawing Figures US. Patent Dec. 23, 1975 Sheet10f2 3,927,751

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U.S. Patent Dec.23, 1975 Sheet20f2 3,927,751

PIN GUIDE FOR PRINTINGJIEAD The present invention relates to a pin guide for print ing head, more particularly of the type in whicha plurality of pins are slidably disposed in a guide way for selective advancement so as to permit mosaic-type printing with a striking printing head.

The pins slide in a very hard and wear-resistant substance such as corundum, which may be natural but is preferably synthetic, of the type of ruby or sapphire. It is known to provide such guides, which are cemented in a recess in a forward surface of the printing head. However, it is difficult to align the guide according to this method, and there is a further risk of misalignment during setting of the cement.

Accordingly, it is an object of the present invention to provide such an arrangement, in which the pin guides can be quickly and easily mounted on the printing head, with the holes defined by the guides precisely oriented relative to the printing head.

Briefly, the object of the invention is achieved by providingfor the guide members of corundum or the like, a support to which they are fixed, the support having at least one reference surface that coacts with a reference surface on the printing head to which the support is detachably secured, and at least one reference surface that coacts with a reference surface on the guides, so as to ensure that the support and hence the guides, are precisely positioned relative to the printing head.

Other objects, features and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of a support and pin guides according to the present invention;

FIG. 1A is a fragmentary perspective view of one embodiment of printing head according to the present invention;

FIG. 1B is a view similar to FIG. 1A but showing a second embodiment of printing head;

FIG. 2 is an enlarged fragmentary front view of a printing head as in FIG. 1A, showing a modified form of support and showing the pin guides in place on the support;

FIG. 3 is a cross-sectional view on the line B-B of FIG. 2; and

FIG. 4 is a view similar to FIG. 3 but showing the printing head of FIG. 1B.

Referring now to the drawings in greater detail, there is shown a device according to the present invention, comprising a pair of guides in the form of small'thin plates 1 of corundum, which may be natural or synthetic, preferably synthetic, known as ruby or sapphire. The plates 1 define between them a plurality of holes 2 by virtue of the fact that the edges of the plates have grooves therein that register with the grooves of the other plate. It is of course to be understood that selectively reciprocable pins (not shown) of the type used for mosaic printing will slide in the holes 2 in the usual manner. The plates 1 are of course of corundum so as to be wear resistant.

A support 3, which can be metal or plastic, is provided for plates 1 and has a forward prismatic portion 4 and a rear cylindrical portion 5. A hole 6 extends lengthwise through support 3 and has a height H which is somewhat greater than the height h of the series of holes 2.

Prismatic portion 4 of support 3 ,has a polygonal recess 7 in which the plates 1 ,arecemented. The bottom ofrecess 7 is perpendicular to the axis of cylindrical portion 5 and the sidewalls of recess 7 are parallel to. that faxis. l

The striking printing head 8, whose first embodiment is shown in FIG. 1A, has a cylindrical hole 9 therethrough for the reception of cylindrical portion 5 of support 3, and a rectangular groove 10 for the reception of prismatic portion 4 of guide 3. The bottom of groove 10 is perpendicular to the axis of hole 9 and the side walls of groove 10 are parallel to that axis. If the cylinder 5 and hole 9 have a diameter of, say, about 5 mm. then the groove 10 and prismatic portion 4 might have a width of about 6 mm. A set screw 11 secures support 3 in head 8; although alternatively, support 3 can be cemented in head 8.

In the embodiment of FIGS. 18 and 4, the printing head 12 is similar to that of FIG. LA but provides only a single lateral reference guide surface 13 for the support 3, which as before is held in the printing head by a set screw 14. b

In FIGS. 2-4, a modified form of support 3 is shown, in which the margins bordering the recess 7 are replaced by projections 15 and 16.

It will of course be appreciated that in either form of the support 3, the margins bordering the recess 7 or the projections 15 and 16 provide locator guide surfaces for the plates 1, which may be cemented to the corresponding base of the support 3 and laterally to the side edges of the recess, so that the plates 1 are precisely oriented relative to the support 3.

The support 3, on the other hand, is precisely ori ented relative to the printing head 8 or 12, by means of the flat guide surfaces that border the prismatic portion 4 of FIG. 1 or that of FIGS. 2-4, which planar surfaces are in area contact with either the opposed sides of the groove 10 of head 8 of FIG. 1A or the single surface 13 of head 12 of FIG. 1B. In short, in all embodiments, the holes 2 are precisely oriented relative to the printing head.

From a consideration of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.

Although the present invention has been described and illustrated in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention, as defined by the appended claims.

What is claimed is:

l. A support for a pin guide, and a head to which said support is secured, said support having a recess therein, a pair of plates cemented in said recess, said plates having opposed edges that define openings between said opposed edges, said support having a cylindrical rear projection that engages in a cylindrical opening in said head, said recess and said plates having a plurality of flat surfaces that are in area contact with each other and that are perpendicular to the axis of said cylindrical rear projection, said recess and said plates having further flat surfaces that are in area contact with each other and that are parallel to said axis, said recess being defined by said flat surfaces thereof, said support and 4 support and said head including at least one flat surface on at leastone projection that extends forwardly from said head, and a setscrew releasably securing said support in said head. 

1. A support for a pin guide, and a head to which said support is secured, said support having a recess therein, a pair of plates cemented in said recess, said plates having opposed edges that define openings between said opposed edges, said support having a cylindrical rear projection that engages in a cylindrical opening in said head, said recess and said plates having a plurality of flat surfaces that are in area contact with each other and that are perpendicular to the axis of said cylindrical rear projection, said recess and said plates having further flat surfaces that are in area contact with each other and that are parallel to said axis, said recess being defined by said flat surfaces thereof, said support and said head having flat surfaces that are in area contact with each other and that are perpendicular to said axis, said support and said head having further flat surfaces that are in area contact with each other and that are parallel to said axis, said further flat surfaces of said support and said head including at least one flat surface on at least one projection that extends forwardly from said head, and a setscrew releasably securing said support in said head. 